Would you do this or not? 1.5 TB on C drive for Exchange 1

[tekinfmgr]

How do you all feel about this configuration? I know that it is best to put databases, logs and OS on different drive arrays but is it really the best for the bang of the buck.

How about this, Windows 2003 Server Ent, brand new IBM 3650, 8 GB RAM, dual 2.0 quad cores and 6X300 GB 15K RPM drives on one big RAID 5 array.

This would be over 1 TB on the C drive as proposed serving email to 700 WAN clients only on Exchange cache mode.

Currently we are running a Dell 2850 with a C drive at 280 GB on RAID 5. It seems to do very well in keeping up with 700 users.

I appreciate your opinions and recommendations.

 

[58sniper]

It's generally not a good idea to do that. That causes a lot of reading/writing on the same drive that houses the OS and paging files, as well as the DBs and TLs. It also contributes to substantial fragmentation.

And RAID 5 sucks anyways. RAID 1+0 is more efficient.

RAID 1 for the OS
RAID 1 for the paging file
RAID 1+0 for the TLs
RAID 1+0 for the DBs



Pat Richard
Microsoft Exchange MVP

 

[xmsre]

With a write penalty of 4, RAID 5 is inappropriate for Exchange 2003 data. Exchange 2003 has a read/write ration of 3:1 or 2:1 (clients in cached mode)

If the write penalty or the proposed RAID type is higher than the read/write ratio of the application, then the RAID type ius not appropriate.

The next problem is that the IBM automated build program, ServeGuide, starts with a fat partition an later converts to NTFS. This results in an allocation unit size of 512 bytes. On top of the poor write performance from RAID 5 in your proposed design, you'll see excessive transactional overhead as IOs are split into 512 byte chunks. THe system will crawl (if that).

Use

RAID 1 for the OS
RAID 1 for the tansaction logs
RAID 1 or 10 or 0+1 for the DBs depending on the IO requirement (you never stated this, see "Optimizing Storage for Exchange Server 2003" for details.)

 

[58sniper]

A star for XMSRE, who always answers the drive related performance questions with great info.

[google]Optimizing Storage for Exchange Server 2003[/google]

XMSRE - time for a good chart w/ links and info - maybe an FAQ?

Pat Richard
Microsoft Exchange MVP

 

[xmsre]

I need to do a FAQ. I currently have a few whitepapers in progress. As soon as they are complete I'll post the links.